Use ApolloClient#stop to clean up MockedProvider client. (#2741)

This method was introduced in apollo-client@2.4.12:
apollographql/apollo-client#4336

package.json

@@ -89,7 +89,7 @@
     "trailingComma": "all"
   },
   "peerDependencies": {
-    "apollo-client": "^2.3.8",
+    "apollo-client": "^2.4.12",
     "react": "^15.0.0 || ^16.0.0",
     "react-dom": "^15.0.0 || ^16.0.0",
     "graphql": "^0.11.0 || ^0.12.0 || ^0.13.0 || ^14.0.0"
@@ -111,7 +111,7 @@
     "@types/zen-observable": "0.8.0",
     "apollo-cache": "^1.1.25",
     "apollo-cache-inmemory": "^1.4.2",
-    "apollo-client": "^2.4.11",
+    "apollo-client": "^2.4.12",
     "apollo-link": "1.2.1",
     "babel-core": "6.26.3",
     "babel-jest": "23.6.0",

src/test-utils.tsx

@@ -42,15 +42,8 @@ export class MockedProvider extends React.Component<MockedProviderProps, MockedP
   }
 
   public componentWillUnmount() {
-    if (!this.state.client.queryManager) {
-      return;
-    }
-    const scheduler = this.state.client.queryManager.scheduler;
-    Object.keys(scheduler.registeredQueries).forEach(queryId => {
-      scheduler.stopPollingQuery(queryId);
-    });
-    Object.keys(scheduler.intervalQueries).forEach((interval: any) => {
-      scheduler.fetchQueriesOnInterval(interval);
-    });
+    // Since this.state.client was created in the constructor, it's this
+    // MockedProvider's responsibility to terminate it.
+    this.state.client.stop();
   }
 }